The invention concerns a matrix printing head with articulated-armature magnets mounted in a circle, with each armature connected to a matrix pin that slides back and forth in a guide more or less in the center of the configuration of magnets, with mechanisms mounted on the armatures that act against the force of attraction exerted by the magnets and return the armatures to a position in which they rest against an armature stop when there is no current flowing through the magnets, leaving an interferric gap of a prescribed width that equals the thickness of the armature plus that of a spacer between each armature and the faces of the magnet's poles, all of which are in one plane, whereby the armatures pivot in the spacer and whereby an armature stop with a flat surface that limits the travel of the armatures is mounted on the faces of the spacer.
A matrix printing head with a similar configuration of articulated-armature magnets is known from German OS No. 2 110 410. The individual magnets in that device are mounted on a base plate along with the armatures, supporting mechanisms, and armature-return mechanisms. The drawback of this system is that, since the interferric gap between the armatures and the magnets is only a few tenths of a millimeter wide, as is necessary for high-speed printing heads, either each armature must be manually adjusted individually with special tools or a lot of expense must be devoted during the manufacturing process to ensure that all the components, specifically the armatures, yokes, and armature-travel limiting structures will remain dimensionally stable. Furthermore, the magnetic coils cannot be allowed to consume too much power due to the small heat-transmission cross-section in relation to the housing of the magnetic head, which dictates and limits the size and operating speed of the magnets.
A matrix printing head with an armature that is turned and milled from a ferromagnetic blank is known from German No. 2 201 049 B2. Although the ends of the armature are in the same plane, they can be aligned in that plane only by turning and not by lapping because of the presence of an elevated edge with a groove for securing the armature that does not allow further processing. Since the armature rests against the yoke in the center, the width of the interferric gap is dictated by the distance between a cover-support surface and the face of the armature, by the thickness of the stop, and by the thickness of the armature, and accordingly depends on, among other factors, the mutual tolerance to which the face and the supporting surface can be turned.
A system of magnets for a matrix printing head with flat pole surfaces and with an armature-supporting surface and an armature surface positioned in the same plane with no interferric gap is known from German No. 3 149 300 A1. Thus, there is no interferric gap to act as an energy buffer, and the force of impression is derived from a spring, which entails precise tolerances. The absence of a definite interferric gap leaves the speed of retraction completely undefined.
A system of articulated-armature magnets for a line printer with an electromagnetic recuperating magnet is known from German GM No. 1 923 036. Its armature is in the form of a bent lever, one arm of which has a hammer mounted on it and the other arm of which constitutes the actual armature. The end of the armature is wider, and the pole surfaces of the magnets, which are positioned on each side, are at an angle to each other, which makes the mechanism complicated to assemble. Since the armature is several times larger than any of its magnetically active regions, it operates much more slowly than a simple magnet.
The object of the invention is to disclose a simple and relatively small system of articulated-armature magnets for a matrix printing head that will dissipate heat well, that will be provided with a well defined and uniform interferric gap as the result of assembly alone, and that will necessitate no additional expenditure from securing the armature.